Autoclave



Oct. 17, 1967 Filed Feb. 25, 1966 w.' VISCHER AUTOCLAVE 2 Sheets-Sheet 1 /0 INVENTOR.

MOW/am W'acb er BUM,

A TTORN s United States Patent 3,347,619 AUTOCLAVE William Vischer, Palatine, Ill., assignor of to Alfred Vischer, Jr., to Alfred Vischer III, %0 to Peter Vischer, to Walter W. Zitzewitz, to Elmer K. Zitzewitz, t0 Gertrude J. Zitzewitz, %0 to Barbara 0. Zitzewitz, and to Gertrude V. Bouton Filed Feb. 25, 1966, Ser. No. 536,523

2 Claims. (Cl. 2198) This application is a continuation-in-part of copending application Ser. No. 274,757, filed April 22, 1963, now abandoned.

The invention relates to autoclaves and has to do more particularly with an autoclave having new and improved means for introducing water into and removing steam from the sterilizing chamber.

The present invention is disclosed in connection with an autoclave of the type commonly used in hospitals, clinics and laboratories for sterilizing instruments and other items, but is not limited to such application. An autoclave of the type to which this invention relates commonly comprises a suitable sterilizing chamber in which the item to be sterilized is subjected to steam under pressure. In order to provide the steam, a small amount of water is introduced into the sterilizing chamber and, after the chamber has been sealingly closed, is heated, as by a heating unit immersed in the water, to boil the water and generate steam which fills the chamber. At the conclusion of the sterilizing operation, the steam is removed from the chamber in order to permit the safe removal of the item which has been sterilized. Accordingly, the chamber is adapted to be selectively connected to a steam condenser which may comprise a section of conduit, usually in the form of a coil, which is submerged in a body of water contained in a tank usually located adjacent the sterilizing chamber. A petcock is provided to control the flow of steam from the chamber to the condenser. When steam is passed through the conduit section, it is condensed and, even though the end of the conduit section is open, no steam is discharged to the atmosphere. Any steam which may pass from the conduit section is absorbed by the water.

Heretofore, in order to supply the water to the sterilizing chamber at the beginning of the sterilizing operation, it has been the practice to provide a water supply conduit between the water tank portion of the steam condenser and the sterilizing chamber and to include therein a manually-controllable petcock which petcock may be opened to permit water to flow by gravity into the chamber from the tank, the tank being located above the level of the 7 bottom of the chamber. Should the operator unintentionally open the petcock in the water supply conduit at a time when there is steam under pressure in the chamber, the steam pressure will subject the water in the tank to a force which may be sufiicient to cause waterto be blown from the tank with resulting inconvenience. Moreover, it is possible that under such circumstances live steam will be exhausted from the tank with resulting possible damage and even danger to the operator.

According to the present invention, there is provided a sterilizing chamber, a water tank located externally of the chamber and containing a body of water, at least a portion of which is located above the level of the bottom of the sterilizing chamber. A steam exhaust conduit leads from the sterilizing chamber to the tank and has an end which opens freely into the body of water in the tank.

The conduit has a condenser portion which preferably takes the form of a coil which is located below the level of the water in the tank. An openable valve which is biased closed is located in the conduit between the sterilizing chamber and condenser portion. The valve can be 3,347,619 Patented Oct. 17, 1967 opened to permit water to fiow through the conduit from the tank into the pressure chamber prior to the sterilizing operation to thereby supply water for the sterilizing operation. The valve can be opened at the conclusion of the sterilizing operation to permit steam to be exhausted from the sterilizing chamber into the condenser and into the body of water. Only a single conduit connects the sterilizing chamber with the tank below the body of water and consequently, so long as the chamber is closed, there is no likelihood of exhausting steam from the sterilizing chamber except through the condenser and into the body of water.

An object of the present invention is to provide a new and improved autoclave.

Another object is to provide an autoclave having novel means for introducing water into the sterilizing chamber.

Another object is to provide an autoclave wherein the introduction of water into and the exhaustion of steam from the sterilizing chamber is under the control of a single two-way valve.

Another object is to provide an autoclave wherein steam can be exhausted from the sterilizing chamber only.

through a steam condenser, so long as the door to the sterilizing chamber is closed.

Another object is to provide an autoclave having a sterilizing chamber, a water tank for containing a body of water, and a single conduit connected between the sterilizing chamber and the tank below the water level, which conduit may be employed to either supply water to the sterilizing chamber or to exhaust steam from the sterilizing chamber.

Still another object is to provide an autoclave having a sterilizing chamber, a water tank for containing a body of water, conduit means connected between the sterilizing chamber and the tank below the water level and a single two-way valve for both exhausting steam from the steri- FIG. 1 with the outer housing removed and with parts broken away and in section;

FIG. 3 is a top plan view of the autoclave of FIG. 1

with certain parts removed to show the interior construc tion; and

FIG. 4 is an enlarged view of a detail, with parts broken 6 way and in section.

The autoclave includes a base 10 and front wall 11 which togethersupport the working parts hereinafter desterilizing chamber or pressure chamber 13 in which the items to be sterilized are to be placed. The casing 12 extends through and is supported at least in part by the front wall 11 and may, if desired, be supported also on the base in a manner not shown.

The casing 12 is closed at its rear end and is open at its front end. The front end is suitably closed, preferably by a closure including a cover 14 carried by a beam 15, pivoted by a pivot pin 16 in a bracket 17. The closure may take any suitable form whereby the sterilizing chamber may be closed and sealed and preferably is similar to the closure disclosed in United States Letters Patent No. 2,538,661 to Alfred Vischer, Jr., patented Jan. 16, 1951, except that in the present structure the beam 15 is pivotu ally attached to the casing 12. A cam 17 having a handle 19 is provided for sealingly holding the cover 14 in closed position. The cover 14 may be opened readily by movim the handle 19 to the opposite side of its pivot from the positionshown in FIG. 3 and then swinging the coverabout the pivot pin and into open position.

Since the open end of the chamber is substantially equal.

in diameter to the chamber, ready access to the chamber is provided and relatively large items may be inserted in the chamber and removed therefrom. When thecover 14 is in closed position and the handle is in the position shown in the drawings, the enclosure provides a steam-tight enclosure and prevents any leakage of steam through the open end of the casing. Except for the conduits hereinafter described, the chamber is entirely closed and sealed.

A suitable rack (not shown) is disposed in the chamber 13 for the purpose of supporting the items to be sterilized above the bottom of the casingqThus, a space is provided below the floor of the rack for water so that the water does not come into contact with the items to be sterilized.

An electrical heating element 20 of known construction is disposed in the bottom of the casing and below the level of the water and. is adapted to be connected to a source (not shown) of electricalenergy. Connected in series with the heater element 20 is a relay (not shown) of known construction which is actuated by pressure-responsive means (not shown) of known construction to disconnect the heating element when the steam pressure in the chamber reaches, a predetermined value. The actuating means (not shown) for the relay (not shown) is adjustable to open the circuit at different values by means of a knob 21 on the front wall 11.

Leading from the chamber 13 and preferably the bottom thereof is a steam exhaust and water supply conduit hereinafter described more in detail. This conduit includes a first section 25 which leads from the chamber 13 and preferably at the bottom thereof, to a valve 26. A second conduit section 27 connects the valve 26 to a condenser section 28 which preferablytakes the form of a coil located in a condenser tank 30 adjacent the casing 12. The condenser tank 30 is adapted to contain a body of water 31 and the end of the condenser section 18 opens freely into the body of water 31 and below the level thereof. Thetank 30 preferably is provided with a cover 32 formed with a fill opening 33.

Referring now particularly to the valve 26 it is normally biased closed but when opened provides communication between the conduit section 25 and the conduit section 27. The valve 26, which preferably is suitably secured to the base 10, includes a T-shaped housing 35 having an axially extending cylindrical valve chamber 36. At one axial end of chamber 36 is an enlarged outlet 38 that communicates with conduit section 27, and at the other end of the chamber is an inwardly directedcircumferential flange 50 separating chamber 36 from enlarged socket 48 formed in the housing 35 at the axial end thereof opposite to outlet 38. Intermediate outlet 38 and flange 50, housing 35 is provided with a radially extending hole termed inlet opening 37 that connects chamber 36 intermediate its ends with conduit 25.

To control communication between inlet 37 and outlet 38, valve element 39 is provided in the form of a rod having at one axial end, plunger 47 slideably mounted in socket 48 of the housing, and at the op posite axial end, piston portion 45 having a cylindrical groove (not shown) in which ring seal 44 is seated in sliding and sealing engagement with the walls of housing 35 that define chamber 36. Intenrnediate the two axial ends of the rod constituting the valve element is another piston portion 42 also having a cylindrical groove therein (not shown) in which ring seal 41 is seated in sliding and sealing engagement with chamber 36. A stem portion of the rod is shownin FIG.

4 4 to the left of the piston portion 42. Reduced portion 43 interconnects piston portion 45 with piston portion 42.

Spring 49, interposed between flange 50 and plunger 47, resiliently urges the valve element 39 to the left as seen in FIG. 4 until piston portion 42 abuts flange 50. In such axial position ofelement 39, the valve is said to be closed because n'ng seal 44 is in chamber 36 and disconnects inlet 37 from outlet 38. Also, ring seal 41. serves to seal socket 48 from. inlet 37 to prevent water or steam in conduit 25 from. leaking from. the device. The valve is said to be open when element 39 is moved. axially to the right as seen in FIGURE4 against spring 49 until piston portion 42 is spaced from flange 50 and piston portion 45 is located in outlet 38. In this axial position, ring seal 44 is no. longer in sealing engagement with chamber 36 and inlet 37 communicates with outlet 38; However, ring seal 41 on piston portion 42 remains interposed between inlet 37 and socket 48 and thus remains veffective to prevent leakage. From the above, it can. be seen that ring 41 serves to always seal socket 48 from inlet 37, regardless of whether the valve is opened or closed.

When portion 42 abuts flange 50 as shown in FIG. 4, the fluid contained in tank 30 is connected via conduit 27 and outlet 38 to the portion of the chamber 36 to the right (FIG. 4) of the seal 44. Pressure chamber 13, however, is connected via conduit 25 to inlet 37, and when the chamber is pressurized, the steamacts against piston portion 45 and exerts an axial force on valve element 39 that aids spring 49 in holding the valve closed.

While one manner of connecting the conduits 25 and 27 to valve 26 is as described above, namely with conduit 27 connected to outlet 38 and conduit 25 connected to inlet 37, the present invention contemplates the reversal of connections.- That is to say, it is possible to obtain satisfactory operation when conduit 27 is connected to inlet 37 and conduit 25 is connected to outlet 38.

It will be seen that when the valve element is in the position shown in FIG. 4, the right-hand ring seal 44 is positioned within the chamber 36 and closes communication between the chamber 36 and the outlet 38. The valve thus is in its closed position and no steam or water.

can flow therethrough. On the other hand, when the plunger 47 is pushed inwardly. (to the right, as ;viewed in FIG. 4), to a position in which the plunger bottoms in the socket 48, the ring seal 44 is moved out of the chamber 36 and into the outlet'38. In this position of the valve element .39, the valve chamber 36 communicates with the outlet 38. The valve thus is in its open position and water and steam can flow therethroughfreely between the inlet tothe outlet.

An operating lever 53 of angular form is pivoted as at 51 to a U-shaped bracket 54 mounted on the base 10 and is provided with an operating knob 52 forwardly of the front wall 11. ,Upon the depression of the knob 52, the lever 53 is rotated counterclockwise (as viewed in FIG. 4) to push the plunger 47 inwardly and open the valve. When the knob 52 is released, the spring 49 returns the valve element 39 to its closed position.

Leading. from the chamber 13, above the level of the water therein and preferably at the rear wall is a section of an air exhaust conduit 55 which connects with a T 56. Connected to one arm of the T 56 is a second section 57 of the air exhaust conduit which leads to an air exhaust .valve 58 preferably located in the tank 30, above the level of the water therein. The air exhaust valve 58 is of known construction and serves to permit air to pass therefrom as pressure is built up in the chamber 13 when -escape from the valve. Thus, it will be seen that the valve 58 will pass air under pressure, but will not pass steam.

Leading from the second arm of the T 56 is a conduit 59 which leads to a thermometer 60 carried by the front wall 11. Thus, steam from the chamber 13 can reach the thermometer 60 which will register the temperature of the steam.

A timer (not shown) of known construction is connected in circuit with the heating element 20 for controlling the energization thereof. The timer may be set by a knob 65 carried on the front wall 11 to energize the heating element for any selected time period within a predetermined range. An audible alarm (not shown) preferably is provided for indicating to the operator the termination of the timed period.

A pilot light 66 is connected in a known manner in circuit with the heating element 20 and is lighted when the heating element is energized to indicate to the operator that the heating element is energized.

A safety thermostat (not shown) is provided which is adapted to deenergize the heating element should the temperature rise above a predetermined value. A reset button 67 is provided for reenergizing the heating element after it has been disconnected by the aforesaid thermostat.

In the operation of the autoclave, a suflicient quantity of water is introduced into the chamber 13 to submerge the heating element 20 and provide sufficient water for the operation. The proper amount of water can be judged by visual inspection. In order to introduce water into the chamber 13, the knob 52 is depressed which opens the valve 26 and permits water to flow from the tank 30 into the chamber 13 by way of the coil 28, the conduit section 27, the valve 26, and the conduit section 25. Upon release the knob 52, the spring 49 urges valve 26 to a closed position.

The item or items to be sterilized are inserted in the chamber 13 and placed on the rack (not shown), which supports the items above the level of the water in the chamber 13. The cover is then closed and locked in position by suitable manipulation of the handle 19 as above described. Thus the chamber 13 is completely sealed except for the outlets provided by the conduit 55. The heating element 20 is then energized to boil the water and thereby fill the chamber 13 with steam under pressure. The knob 21 is set to provide the desired temperature and/or pressure and the timer is set to provide the desired time period of sterilization.

As steam is generated in the chamber 13, it forces air from the chamber through the conduit section 55, the T 56, the conduit section 57, and the air exhaust valve 58. However, the air in the chamber 13 is heated by the steam being generated and when the air passing through the air exhaust valve 58 reaches the preselected temperature, the valve 58 closes.

As steam continues to be generated, the temperature rises to the preselected sterilizing temperature and is main tained at that temperature for the predetermined period of operation. At the termination of this period, the alarm sounds and the operator knows that the sterilizing period has terminated. The operator then depresses the knob 52 to open the valve 26 which allows the steam to be exhausted from the chamber 13. The steam thus passes through the valve 26 and into the condenser portion 28 in which the steam is condensed and forced in the form of condensed water into the body of water 31. Should, however, any steam in the chamber not be fully condensed, it will not escape but will be absorbed in the body of water 31. Owing to the pressure of the steam in the conduit section 25, the valve 26, the conduit section 27, and the condenser section 28, no water will flow into the chamber from the water tank 30 until the pressure in the chamber 13 is suitably reduced. The operator, by observing the thermometer 60, can determine when the steam has been suitably reduced in temperature and can then release the knob 52 to prevent the flow of water into the chamber 13.

The operator then opens the cover 14 and removes the sterilized item or items. The autoclave is then in condition for a second cycle of operation such as above decontrol knob 52 controls both the exhaust of steam from the chamber 13 and the admission of water into the chamber 13. Thus, should the operator operate the knob at any time when steam is present in the chamber 13, the steam will merely be exhausted into the body of water 31 and will not be exhausted to the atmosphere. Thus there is no likelihood of inconvenience, damage, or injury to the operator which otherwise might result if live steam were exhausted from the chamber 13 into the atmosphere adjacent the autoclave. The air exhaust valve 58 is efiective to prevent exhaustion of steam therethrough and consequently the only path for the exhaustion of steam from the chamber 13 is through the condenser 28 and the body of water 31. While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein which are within the true spirit and scope of the invention as described in the appended claims.

What is claimed is:

1. Steam autoclave comprising:

a pressure chamber adapted to hold steam under pres sure;

a condenser adapted to hold a supply of liquid comprising substantially water for condensing steam supplied thereto;

a first conduit communicating with the interior of said chamber through an opening in the first end of said first conduit;

a second conduit communicating with the interior of said condenser through an opening in the first end of said second conduit;

valve means, communicating with the interiors of said first and said second conduits through the second end of said first conduit and the second end of said second conduit, for connecting said second ends of said first and second conduits when said valve means is in an open position whereby steam and said liquid may pass between said chamber and said condenser and for disconnecting said second ends of said first and second conduits when in a closed position; said valve means comprising:

a housing having an axial aperture extending therethrough, one end of said aperture constituting an outlet and being connected to the second end of one of said first and second conduits;

said outlet having a larger radial size than the remainder of said axial aperture;

said housing having a radial aperture that connects said axial aperture to the second end of the other of said first and second conduits;

first and second seals each engaging the surface of said housing and being of suflicient size to seal said axial aperture;

valve-element means, having a first location and a second location within said housing, for positioning, when in said first location, said first seal on the opposite side of said radial aperture from said outlet and said second seal within said outlet, whereby said outlet and said radial aperture communicate with each other to open said valve means, and for positioning, when said valve-element is in said second location, said first seal within said axial aperture on the opposite side of said radial aperture from said outlet and said second seal within said axial aperture housing between said radial aperture and said outlet, whereby said radial aperture and said outlet are sealed from each other;

said first and second seals being connected to said valveelement to move therewith;

biasing means for exerting force against said valveelement means in the direction of said second location; and

manually operable means, engaged with said valveelement means, for manually moving the same against the action of said biasing means toward said first location, whereby the interiors of said chamber and said condenser may be interconnected.

2. Apparatus in accordance with claim 1, in which said valve-element means includes an axial shaft interconnecting said first and second seals in spaced-apart relation to each other and being axially movable in said axial aperture, said seals being spaced on said shaft-a sufficientdistance apart so that one of said seals is positioned within said outlet while the other of said seals is positioned on the opposite side of said radial aperture as said outlet when said valve means is in its open position and one of said seals is positioned between said radial aperture and said outlet within said axial aperture and the other is positioned on theopposite side of said radial aperture as said outlet when said valve is closed, and wherein said radial aperture is connected to the second end of said first conduit and said outlet is connected to the second end of said second conduit whereby the steam pressure tends to exert a balanced force on said valve-element means while said valve is in a closed position.

References Cited UNITED STATES PATENTS 84,992 12/1868 Bull et al. 251282 1,172,739 2/1916 Roehrich "251-282 1,204,954 11/1916 Davison 251-282 X 2,000,367 5/1935 Williamson et al. 21-104 X 2,456,152 12/1948 Schneider 21-97X 2,510,393 6/1950 Fraseretal. 21104X FOREIGN PATENTS 783,964 10/1957 Great Britain.

MORRIS O. WOLK, Primary Examiner.

I. ZATARGA, Assistant Examiner. 

1. STEAM AUTOCLAVE COMPRISING: A PRESSURE CHAMBER ADAPTED TO HOLD STEAM UNDER PRESSURE; A CONDENSER ADAPTED TO HOLD A SUPPLY OF LIQUID COMPRISING SUBSTANTIALLY WATER FOR CONDENSING STEAM SUPPLIED THERETO; A FIRST CONDUIT COMMUNICATING WITH THE INTERIOR OF SAID CHAMBER THROUGH AN OPENING IN THE FIRST END OF SAID FIRST CONDUIT; A SECOND CONDUIT COMMUNICATING WITH THE INTERIOR OF SAID CONDENSER THROUGH AN OPENING IN THE FIRST END OF SAID SECOND CONDUIT; VALVE MEANS, COMMUNICATING WITH THE INTERIORS OF SAID FIRST AND SAID SECOND CONDUITS THROUGH THE SECOND END OF SAID FIRST CONDUIT AND THE SECOND END OF SAID SECOND CONDUIT, FOR CONNECTING SAID SECOND ENDS OF SAID FIRST AND SECOND CONDUITS WHEN SAID VALVE MEANS IS AN OPEN POSITION WHEREBY STEAM AND SAID LIQUID MAY PASS BETWEEN SAID CHAMBER AND SAID CONDENSER AND FOR DISCONNECTING SAID SECOND ENDS OF SAID FIRST AND SECOND CONDUITS WHEN IN A CLOSED POSITION; SAID VALVE MEANS COMPRISING: A HOUSING HAVING AN AXIAL APERTURE EXTENDING THERETHROUGH, ONE END OF SAID APERTURE CONSTITUTING AN OUTLET AND BEING CONNECTED TO THE SECOND END OF ONE OF SAID FIRST AND SECOND CONDUITS; SAID OUTLET HAVING A LARGER RADIAL SIZE THAN THE REMAINDER OF SAID AXIAL APERTURE; SAID HOUSING HAVING A RADIAL APERTURE THAT CONNECTS SAID AXIAL APERTURE TO THE SECOND END OF THE OTHER OF SAID FIRST AND SECOND CONDUITS; FIRST AND SECOND SEALS EACH ENGAGING THE SURFACE OF SAID HOUSING AND BEING OF SUFFICIENT SIZE TO SEAL SAID AXIAL APERTURE; VALVE-ELEMENT MEANS, HAVING A FIRST LOCATION AND A SECOND LOCATION WITHIN SAID HOUSING, FOR POSITIONING, WHEN IN SAID FIRST LOCATION, SAID FIRST SEAL ON THE OPPOSITE SIDE OF SAID RADIAL APERTURE FROM SAID OUTLET AND SAID SECOND SEAL WITHIN SAID OUTLET, WHEREBY SAID OUTLET AND SAID RADIAL APERTURE COMMUNICATE WITH EACH OTHER TO OPEN SAID VALVE MEANS, AND FOR POSITIONING, WHEN SAID VALVE-ELEMENT IS IN SAID SECOND LOCATION, SAID FIRST SEAL WITHIN SAID AXIAL APERTURE ON THE OPPSITE SIDE OF SAID RADIAL APERTURE FROM SAID OUTLET AND SAID SECOND SEAL WITHIN SAID AXIAL APERTURE HOUSING BETWEEN SAID RADIAL APERTURE AND SAID OUTLET, WHEREBY SAID RADIAL APERTURE AND SAID OUTLET ARE SEALED FROM EACH OTHER; SAID FIRST AND SECOND SEALS BEING CONNECTED TO SAID VALVEELEMENT TO MOVE THEREWITH; BIASING MEANS FOR EXERTING FORCE AGAINST SAID VALVEELEMENT MEANS IN THE DIRECTION OF SAID SECOND LOCATION; AND MANUALLY OPERABLE MEANS, ENGAGED WITH SAID VALVEELEMENTS MEANS, FOR MANUALLY MOVING THE SAME AGAINST THE ACTION OF SAID BIASING MEANS TOWARD SAID FIRST LOCATION, WHEREBY THE INTERIORS OF SAID CHAMBER AND SAID CONDENSER MAY BE INTERCONNECTED. 